T

CYST IN FECES (TROPH HAY ALSO BE if< FECAL STREAM)

ADVERSE ENVIRONMENTAL

CONDITIONS OR FOR REPRODUCTIVE REASONS / CYST FORMED

IN THE INTESTINE CYST WITH EIGHT NUCLEI EXCYSTS

CYST IN FECES (TROPH HAY ALSO BE if< FECAL STREAM)

CVST AS A. CONTAMINANT OF FOOD OR ■

MATURE

CYST FORMED

WATER INGESTED

Figure 1-7. Life cycle of Entamoeba coli.

SIZE: 10 to 50 mcm. SHAPE : Irregular. NUCLEUS: Vesicular, dispersed. NUMBER: One.

PERIPHERAL CHROMATIN: Course granules; irregular size and distribution KARYOSOME: Small but larger than e. histolytica and usually eccentric. NUCUEOPLASM: Not as clean as E. histolytica. CYTOPLASM:

APPEARANCE: Dirty, vaculoated, coarsely granular. INCLUSIONS: Yeasts, molds, bacteria. MOBILITY: Nondirectional with blunt pseudopodia.

Figure 1-8. Trophozoites, E. coli. CYST

SHAPE : Spherical.

NUCLEUS: Vesicular, dispersed.

NUMBER: 1-8; mature cyst has 8.

PERIPHERAL CHROMATIN: Course granules; irregular size and distribution KARYOSOME: Small but larger than e. histolytica and usually eccentric. NUCUEOPLASM: Not as clean as E. histolytica. CYTOPLASM: Dirty.

CHROMATOID BODIES: Splintered-ends; uneven; pointed ends; resembles shock of wheat. GLYCOGEN: Diffused.

ORGANISM 4 -- Entamoeba polecki

GENERAL CHARACTERISTICS

COMMON NAME: None.

GEOGRAPHICAL DISTRIBUTION: Papua, New Guinea.

PATHOGENESIS: Occasional parasite of man.

HABITAT: Intestines.

INTERMEDIATE HOST: None.

RESERVOIR HOST: Pigs and monkeys.

INFECTED FORM: Mature, uninucleated cyst.

MODE OF INFECTION: Ingestion.

LABORATORY IDENTIFICATION:

SPECIMEN SOURCE: Feces.

LIFE CYCLE

TROPHOZOITE 1 N COLON DF MAN

SIMPLE flI NARY FISSION WITH NUCLEAR

i division occurs in the intestine

UN]NUCLEATED CYST EXCYSTS

ADVERSE ENVIRONMENTAL CONDITIONS CAUSE

formation

CYST

CYST IN FECES ÎTfiOPH MAY ALSO BE IN FECAL STREAM )

CYST AS A

contaminant of food or water ingested

UNINUCLEATED CYST UNDERGOES MATURATION

Figure 1-10. Life cycle of Entamoeba polecki.

SIZE: 10 to 25 mcm. SHAPE : Irregular. NUCLEUS: Vesicular, dispersed. NUMBER: One.

PERIPHERAL CHROMATIN: Fine and course granules; may be even or uneven; could be masses at one end.

KARYOSOME: Small; discrete; usually eccentric; may be fragmented. NUCUEOPLASM: Usually dirty. CYTOPLASM:

APPEARANCE: Very dirty and vaculoated. INCLUSIONS: Bacteria. MOBILITY: Nondirectional (occasionally directional).

Entamoeba polecki (cont)

Figure 1-11. Trophozoite, E. polecki.

SIZE: 9 to 18 mcm. SHAPE : Spherical to oval. NUCLEUS: Vesicular, dispersed. NUMBER: One.

PERIPHERAL CHROMATIN: Fine and course granules; may be even or uneven; could be masses at one end.

KARYOSOME: Small; discrete; usually eccentric; may be fragmented. NUCUEOPLASM: Usually dirty. CYTOPLASM:

CHROMATOID BODIES: Many; irregular shape with pointed ends.. GLYCOGEN: Diffused.

INCLUSION MASS: Unknown nature but typical of the oranism.

Figure 1-12. Cyst, E. polecki.

ORGANISM 5 -- Naegleria fowleri

GENERAL CHARACTERISTICS

COMMON NAME: None.

GEOGRAPHICAL DISTRIBUTION: Australia, Europe, and America.

PATHOGENESIS: Primary amebic meningoencepha (PAM).

HABITAT: Usually free living; the meninges in man.

INTERMEDIATE HOST: None.

RESERVOIR HOST: None known.

INFECTED FORM: Biflagellated trophozoite.

MODE OF INFECTION: Active penetration through the nostrils.

LABORATORY IDENTIFICATION:

SPECIMEN SOURCE: Cerebral spinal fluid.

LIFE CYCLE

Bt flagellated ►trophozoite in stagnant water

Bt flagellated ►trophozoite in stagnant water when optimal conditions résumé

excystation occurs

ej flagellated or cyst form enters man adverse environmental conditions cause dead end adverse environmental conditions cause through nostrils

dead end converts to amebic form in nasal passages cycle exists in man hbs imple 01 nary f iss i on with nuclear division occurs amebic form penetrates to meninges of brain

Figure 1-13. Life cycle of Naegleria fowleri.

Figure 1-13. Life cycle of Naegleria fowleri.

Naegleria fowleri (continued)

FREE-LIVING TROPHOZOITE

Indistinguishable from N. gruberi, a free living organism isolated from soil. SHAPE: Pear shape. FLAGELLA--ANTERIOR: 2 to 4.

SIZE: 10 to 25 mcm. SHAPE : Elongated to oval, NUCLEUS: Vesicular, dispersed. NUMBER: One.

PERIPHERAL CHROMATIN: Finely granular and evenly distributed. KARYOSOME: Some small but larger than E. histolytica. NUCUEOPLASM: Clean to dirty. CYTOPLASM:

APPEARANCE: Finely granular. INCLUSIONS: Cellular debris. MOBILITY: Nondirectional and sluggish.

AMOEBIC TROPHOZOITE
Figure 1-14. Stages of N. fowleri. (cont)

SIZE: 8 to 12 mcm. SHAPE : Oval to spherical. NUCLEUS: Vesicular, dispersed. NUMBER: One.

PERIPHERAL CHROMATIN: Finely granular and evenly distributed. KARYOSOME: Some small but larger than E. histolytica. NUCUEOPLASM: Clean to dirty. CYTOPLASM:

CHROMATOID BODIES: None detected. GLYCOGEN: Diffuse

Figure 1-14. Stages of N. fowleri. (concluded)

Hartmanella and Acanthamoeba species

GENERAL CHARACTERISTICS

Pathogenesis--(mild disease process). At one time, the disease caused by N. fowleri was thought to be caused by these two genera. At present, it is believed that there is no pathogenicity caused by Hartmanella species, but Acanthamoeba species are still believed to produce infection in man.

Laboratory identification-same as N. fowleri except for the absence of the flagellated stage.

COMMON NAME: None.

GEOGRAPHICAL DISTRIBUTION: Cosmopolitan.

PATHOGENESIS: Nonpathogenic.

HABITAT: Intestines (colon).

INTERMEDIATE HOST: None.

RESERVOIR HOST: None.

INFECTED FORM: Mature, quadrinucleated cyst.

MODE OF INFECTION: Ingestion.

LABORATORY IDENTIFICATION:

SPECIMEN SOURCE: Feces.

ORGANISM 6 -- Ensolimax nana

GENERAL CHARACTERISTICS

LIFE CYCLE

trophozoite in colon of man trophozoite in colon of man simple binary fission with nuclear division occurs adverse environmental conditions cause fornation cyst

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